Help solve the mystery

Each year I replace my winter losses by purchasing frames of bees/brood from a friend of mine who is a commercial beekeeper. His bees go to California for almonds and then to Washington for apples. By the first or second week in May they are back here in ND. I meet him at his yard, help him make splits, pull frames for my nucs (3 or 4 frames/nuc) and head home. I order queens separately and queen the nucs in my own yards.

This plan has worked well for both of us for some time. I even buy frames for other hobby beekeepers nearby and they make up their own nucs that way.

This year though was (very unsuccessfully) different and we can not figure out what happened. Two features were different this year:

First, because of the late spring, the bees were late getting back - third week of May.

Second, the bees that came back were also lighter in terms of stores and numbers than in past years.

We made splits and pulled frames as always. When I returned home, I set up the nucs, introduced the queens and put 1:1 syrup and pollen patties on them.

All of the queens were accepted - but then it got strange:

Almost every nuc failed. I made up 11 - only three made it. The failed nucs never took down a drop of syrup, took any of the pollen patty, queens never really started laying (maybe only palm sized patches of brood) and the bees tended to be more aggressive than in past years. Over the next month - every nuc dwindled to about a fist size clump of bees and died. I would find the queens walking around on the comb with maybe 200 bees and that would be it.

The queens used came from three different sources and were three different strains (MN Hyg, Carn, Russian). Of the three nucs that survived: 1 MN Hyg (1 for 3), 2 Russian (2 for 2).

I talked with the commercial beekeeper and he reported the same pattern - only on a much larger scale. His splits did the same thing. He treated with Fumigilin - didn't matter. His mite levels were low (he monitors by sampling hives - not testing every one). His splits just dwindled and died like mine.

We can't think of a disease that would cause this kind of failure. We thought of pesticides, but his bees go to the same orchards every year with no problems before.

Did the orchard owner change pesticides? Does the commercial beekeeper change out old comb, after years of use, pesticides can build up in the comb even if the bees are not directly exposed to the pesticide over time. That's my two cents worth. Jack

Can't say about the orchard owners pesticides. I do know that the comm. beek cycles his frames on a 3-5 year schedule (depending on how they look). All his frames are identified on the top bar as to the year that they go into service. Based on that, I wouldn't suspect pesticide build up to have been the problem.

With the weather the way it has been around the US of A this year I would be willing to bet you got a group of queens that was not properly mated. You didnt mention how many bees you move over when making nucs if the majority are field bees they are wore out and hives dwindled as they died off and the others was unable to care for what was there as they hatch or basically going below the critical mass

Well, I thought that it might be a batch of bad queens too (and it still might) - but my queens came from three different sources. Add that to the comm. beeks queen source and you have hives failing with queens from Texas, Ohio, California, Georgia. The queens also came later (end of May/beginning of June). Still, I had thought of that and it could be.

The nucs are made up with frames of brood (both capped and open) along with the bees covering brood. So there is probably a mix of field and house bees with plenty of bees to come.

humm... the fellow who is president of the ABF made some comment in a recent addition of the ABF news letter with some implication that there may be a sub lethal (for the bees) combination of pesticide and herbicide used by the almond growers. I think he stated (no exact quote here I hope you understand) is that established hives brought out of the almonds (somewhere in north Florida I think???) and fed would not grow.

I overwinter (or try to) here in ND. Winter was harder than normal - but otherwise not out of the ordinary. Spring here was very late (if felt as though we went from winter to summer with no spring). We actually had a blizzard with 8" of snow in mid-April - so that wasn't entirely normal.

It has also been very wet. We have almost 17" of moisture for the year so far. Average annual precip is only 13" (hence my previous post on chalkbrood!).

so since you mentioned chalkbrood was there any recognizable diseases in the batch of nucs you made up?

given the kinds of stuff that is increasingly being sprayed in citrus, almonds and apples I would suspect you are seeing a synergistic effect of various sprays.

it kind of makes you wonder when (as you stated in post #1) that hives come back later but lighter????

ps... I heard a 'quite' similar reports from a group of hobby beekeepers from Virginia at this year's North American Bee Keeping Convention in regards to nucs obtain (purchased by clubs in numbers in the prior season) from south Georgia. since I could track the trail of pollination bees out of the almonds I suspect at the time that something along the same lines was happening there.

There weren't any signs of traditional diseases in the nucs. The chalkbrood episode occurred months after in my hives/nucs that survived. I suspect that was due to how wet it has been and has since cleared up.

I also had a single case of sacbrood this year - but that occurred in an established, three-year old hive, not one of the nucs.

The hives came back later because the apple grower in Washington wouldn't release them until the bloom was over. Apparently, this year, everything has been late and the apple bloom finished up two weeks later than normal.

It is strange that they came back lighter. More interesting (to me) though is the report that something similar happened in the south.

Your theory regarding the synergistic effect of the sprays has merit (at least in my opinion). How could that be tested or confirmed? Or a better question might be: should a repeat of the pattern next year be expected?

Along the line of synergistic effect like tec. suggest, comes to mind of how much necture and pollen the bees get from the new variety of apple trees that have been developed over the past years? I have heard that hives that have been rented to pollenate cucumbers have to be fed or they would starve. Jack

Tyro writes:
Your theory regarding the synergistic effect of the sprays has merit (at least in my opinion). How could that be tested or confirmed? Or a better question might be: should a repeat of the pattern next year be expected?

tecumseh:
the levels of contamination would be real low. you would have to wait for ever but you could likely send wax samples to the bee lab in Maryland. the way funding is there the information would likely be worth little by the time you got any results.

I think the pollinators folks were trying to encourage the various fruit and nut growers to curtail spraying while the bees were in the orchards. Totally guessing here...> I would think the worse the season the more grove owners may need to spray.

I think what Jack said about and the late season might explain part of why the hives were light... but weak or poisoned bees will not put up much nectar either.

To your last question I would say maybe... a good season cleans up a lot of problems and a poor season may well produce the same results.